(a) What is the basis of formation of the spectro-chemical series?
(b) Draw the structures of geometrical isomers of the following coordination complexs: `[Co(NH_(3))_(3)Cl] and [CoCl_(2)(en)_(2)]^(+)`
(en= ethylenediamine and atomic number of Co is 27)

Explanation

(i) Spectro-chemical series : The arrangement of ligands in order of their increasing field strength i.e., increasing crytstal field splitting energy(CFSE) value is called spectro-chemical series.
(ii) The cis and tans isomrs of `[Co(NH_(3))_(3)Cl_(3)]` may be represented as
(ii) ` [CoCl_(2)(en)_(2)]^(+)` ion exists in two geometrical isomers as shown below.